Balancing Act
by DarlingJames
Summary: Moriarty hires an expert criminal to infiltrate 221B, but can she hide the truth from the great Sherlock Holmes? Rose finds she has to balance Sherlock and Moriarty - and one mistake could mean death. Sherlock/OC, a little Moriarty/OC, M for later chapters.


Chapter One – The Girl and the Spider

The girl sat in the middle of the bed in the dingy hotel room, zoned into her laptop, typing at a furious pace. Her eyes were glassy as a sharp rap at the door distracted her. She flung her head around.  
"What the hell do you want now?" she said, irritated.  
"He's here again." Said the voice at the door. She rolled her eyes and slipped off the bed, grabbing a gun from the bedside table.  
"Fine. I'll be out in a minute, keep him in the front room."  
She opened the door and sighed, ruffling her brown hair. Business negotiations always bored her, she'd rather one of her lackeys do the fine print. But this customer was different, he wouldn't settle for less than the ringleader. She opened the door to the sitting room.  
"Well now, Mr…." she started. A dark-haired man sat in one of the scrappy armchairs, wearing an expensive suit.  
"Call me Moriarty, dear." He drawled_. Hm. Irish. _  
"I understand you demanded to see me?"  
"_Demanded_ is a bit dramatic, don't you think?"  
"You shot four of my men."  
"Simply business, darling."  
"Well, what do you want?" she snapped.  
"Your help, of course." He said, rising from the chair. He strolled closer towards her. "I need a mole."  
"Well, that's my specialty. What's the organisation?"  
"Well, it's more of a home business. You've heard of Sherlock Holmes, of course."  
"Naturally." She said, now curious.  
"Well, I have a plan." He said, pulling out a cigarette and lighting it. He offered one to her, but she shook her head. "I'll need someone to worm their way into his flat, collect information. Be my eyes and ears, so to speak." She quirked an eyebrow.  
"And what, exactly, is this special plan?"  
Moriarty reached out and took a tacky fabric flower from the vase on the coffee table. He looked her directly in the eyes and flicked his lighter, setting the carnation on fire. She watched as the ashes floated onto the carpet.  
"Chaos." He smirked.

* * *

Sherlock Holmes was so very, very bored. Slumped in his armchair, violin on his lap, he grumbled as Mrs Hudson set a tray of tea and biscuits on the coffee table, attempting to set a few papers in order before she left.  
"Don't touch a thing, everything is exactly where I want it." He said, but didn't move to stop her. "Please John, there must be a case! This is ridiculous."  
John shuffled the newspaper. "Nope. You could check the website yourself once in a while, you know."  
Sherlock groaned and stood to get John's laptop. He quickly cracked the password 'protection', opening his email.  
"No. No. No! Oh, for goodness' sake." He mumbled, scrolling through. He stopped suddenly.  
"Oh!"  
"What? Anything good?" John asked.

_Dear Mr Holmes,  
I am sorry for bothering you, but I have something of an issue that has been bothering me lately. I'm not usually one to be superstitious, but I can't see any other possible explanation.  
You see, for the last three months, there has been strange symbols appearing in all the flats in my building – except for mine. They never fail to appear overnight, but even when the residents stay awake or set cameras, they can never catch a culprit. They just appear as if by magic on the walls.  
Do please help,  
Rose McGillon  
Flat 19, Beaufort House, Knightsbridge_

"Stupid woman. Of course it's not supernatural." Sherlock sighed, passing the email to John. "Still, better than no case at the moment. Come on!" he said, practically pulling John out of his armchair.

_-Thirty-five minutes later-_

"Bit of a flashy place, isn't it?" John said, as they stood in front of a block of pretty white flats with manicured gardens. It was definitely high class, and without a doubt expensive.  
"Well, you could do worse in central London, that's for sure." Sherlock said. They found their way to flat 19 and rang the doorbell.  
The door opened after a moment, and a young brunette woman stood in the doorway. She smiled.  
"Oh! I wasn't expecting you so soon, come in!" She said, stepping aside. Sherlock flounced in and immediately began talking, interrupting John's introduction.  
"Well, let's not waste time." He said. " Tell me everything."  
"uh…well, sure. Do sit down." She said, pointing to the lavish couches in the centre of the room.  
"Now. To be honest, I've only just moved here." She said, sitting. "But ever since I have there's been strange symbols being painted on the neighbour's walls in the middle of the night-"  
"Have you got any pictures of them?" Sherlock interrupted. She frowned.  
"Yes, of course. Just a minute." She pulled out her phone and showed him a photo.  
Sherlock frowned. The symbol was almost like a target with a diagonal line through the middle, painted in dark red spray paint.  
"They always appear in the middle of the night, and disappear during the day. Nobody has ever seen anyone paint them, even with CCTV. We don't know what to do."  
"Are there any cleaners for the flats? Anyone who comes in regularly?" John asked. Sherlock rolled his eyes.  
"Only a gardener and three cleaners, on Mondays and Fridays. The symbols are there almost every day."  
Sherlock frowned again and leapt up, inspecting the apartment from top to bottom.  
"Has this symbol ever appeared on your walls?" he asked, inspecting a curtain.  
"Well, no. not once, actually."  
Sherlock eyed her suspiciously. "But on everyone else's?"  
"Yes. Do you have any ideas, Mr Holmes?" she asked, getting impatient.  
"Approximately nine." He said. She frowned. He lifted the carpet and hmmed. "Maybe eight."  
"Well, if one of those eight ideas could help us, feel free to share." Said John.  
Sherlock glared at John and gave a grin. "All in due time John. Now, we should be going. Thanks very much, Miss McGiddon."  
She paused. "McGillon. Rose McGillon." She said.  
"Great. We'll be in touch." Sherlock said, walking quickly out of the room.  
As Sherlock waved down a cab, John looked confused. "What was all that about?"  
"She isn't who she says she is. Didn't you notice? She's wearing a dress, but she's leaning slightly to one side, like she's used to carrying something heavy on her hip, like a gun. She was slow to correct my misuse of her name, so even she isn't used to it yet."  
"She could have just gotten divorced? Some people use their old name after that."  
"If that was the case, she's calling herself 'Miss' a bit quick. No, it's a false name. Witness protection, maybe? An ex-officer?" He mumbled to himself.  
John sighed as Sherlock got into the cab.  
"Get the next one. I need to think." Sherlock said, slamming the door.  
_What a cock_. John looked at the now-deserted street and groaned in frustration, beginning the walk to the main road.

* * *

'Rose McGillon' Grumbled as she sat on the fancy new couch in her fancy new apartment. That Moriarty was a wanker, but he had everything sorted for her – name, backstory, passport, even birth certificate. She was, for all intents and purposes, Rose.  
The detective was attractive, she'd give him that. And those cheekbones, god almighty. This assignment wouldn't be a hardship.  
She made a cup of tea and opened her laptop, pulling up a search for Sherlock Holmes.  
She smirked. Poor darling.  
He wouldn't know what hit him.


End file.
